According to the account given by the author of the commentary, who was a disciple of the poet, an Ismaili scholar called Abu'l-Haytham Jurjani put a number of philosophical and theological riddles into verse, but was prevented by death from completing his didactic poem by answering the questions which he has propounded. We have a parallel to this in the long poem inserted in the fourth epistle of the fourth part of the Epistles of the Ikhwan al-Safa' (ed. Cairo, IV, 191-5) which contains a series of questions about Ismaili theology to which no answers are forthcoming; and perhaps we may guess that also our author was not really very serious about his intention to add the answers in a second part but rather meant his collection of posers as a jeux d'esprit upon which his readers might exercise their knowledge. Be it as it may, a disciple of Abu-l-Haytham whom the editors propose to identify with Muhammad b. Surkh of Nishapur (named by al-Bayhaqi as the author of a commentary on Abu'l-Haytham's poem) undertook to write a running commentary in which he would solve the riddles posed. It is clear that Abu'l-Haytham and his disciple both lived in the fourth/tenth century, but further details are not known. The editors think that Abu'l-Haytham must have been a contemporary of the Persian poet Rudaki (d. 329/940-1), because the commentator says (in connection with a certain doctrine he quotes in the name of his master) that many have misunderstood his master's real meaning, yet nevertheless boast themselves as wise, citing a verse from Shahid expressing the poet's self-assertion, another from Mus'abi, and a third ('To me belongs the secret of the wise in Khurasan') from Rudaki, with the comment: 'it was not so, because if it were so, he would have been pious'. From this, the editors deduce that these poets were amongst those who knew Abu'l-Haytham's theory but misunderstood it; thus Abu'l-Haytham must have lived at the very beginning of the fourth/tenth century. (On the other hand they consider it possible that the commentator, Muhammad b. Surkh, might be identical with a teacher of Nizami-i 'Arudi--twelfth century--with a similar name. The two assumptions are obviously mutually exclusive; but the latter identification is improbable in any case). I doubt whether this interpretation of the passage is certain, and would rather assume that the verses are quoted in a general way as examples of misplaced self-assurance; if so, we have no external indication about the exact date of the poet and his commentator.

We may assume that the explanations of the commentator, who for nine years was a disciple of Abu'l-Haytham, approximately correspond to Abu'l-Haytham's intentions; in any case it is rather the detailed commentary than the laconic text that is of interest to us.

The commentator's explanations provide precious materials for the knowledge of the ideas current among the Ismaili circles of Persian in the fourth/tenth century. Abu'l-Haytham's poem, and in consequence also his disciple's commentary, deal without much order with various philosophical and theological problems. The philosophic-theological system professed by them is on the whole that of al-Nasafi and Abu Ya'qub al-Sijistani which was the standard system held by the Ismailis of Persia in the fourth/tenth century. (When we know Abu Ya'qub's extant works in more detail we shall no doubt be able to examine the relation between his doctrines and those of Abu'-l-Haytham and his disciple). We encounter the main features of this system: the creation from nothing (ibda') through the divine command (amr) of the spiritual substances; intellect, soul, nature. Some details concerning these are discussed, but all kinds of miscellaneous problems are also introduced. Some of the questions concern rather elementary problems, for example logical notions derived from the Isagoge and the Categories and their commentaries; but even these are not without interest for the history of Islamic philosophy. In the eleventh century Abu'l-Haytham's qasida received another commentary by the hand of Nasir-i Khusraw, which in its turn sheds much light on that author's thought; Nasir-i Khusraw's commentary, entitled Jami' al-hikmatayn, was published in 1953 by the same editors, and the edition reviewed in BSOAS, XV111, 2, 1955, 398-9. The literary problems are discussed in the Persian introduction (by M. Mo'in). The French introduction (by H. Corbin) contains, in addition to the discussion of the same subject, lengthy analyses and paraphrases of some of the main passages, which are often helpful in bringing out their intention. On the other hand it is not always easy to follow the style of this introduction and some of the ideas expressed there are rather far-fetched. The author of this introduction seems to despise the historical approach to the interpretation of ideas: many of his views on the history of Ismaili thought seem to the reviewer rather doubtful, and in the cases where he attempts an historical analysis he is not always successful. While the internal analysis of the text is, as I have said, often illuminating, little has been done in the way of annotating the philosophical terms and quotations and the sources of the philosophical notions used by the commentator. There is ample scope left for work of this kind, which alone can make the text really useful for the history of Islamic philosophy. Obviously this subject cannot be pursued far in a review, but I should like to give at least a few examples. The definition of intellect quoted by the commentator (p. 92) in the name of the philosophers: ----------------- [read so for -----] 'the intellect is a simple substance which perceives things in their truth', is that given by al-Kindi (see Rasa'il al-Kindi al-falsafiyya, ed. AbuRida, p. 165, and S.M. Stern, "notes on al-Kindi's treatise on definitions'. JRAS, 1959, 1-2, p. 34, n.1). Similarly there is some need for clarification when, in order to show that the philosophers acknowledge the existence of angels, the commentator quotes (p.32) the definition of many by Aristotle (in fact by the commentators of Aristotle): 'rational and mortal living being'; 'living being' indicates the genus, 'rational' the differentia distinguishing man from the animals, 'mortal' the differentia distinguishing man from the angels. In effect, in some of the Alexandrian commentaries on the Isagoge we find this distinction (see Ammonius on the Isagoge, Commentaris in Aristotelem graeca, Iv, 3, p. 100, II. 13-15; Elias on the Isagoge, ibid., XVIII, i, p. 82, II. 140-17; Philoponus on the Categories, ibid, XIII, 1, p. 159, II. 7-8 [the editor considers this passage to be an interpolation]. From such commentaries the distinction passed into Arabic philosophical literature and we find it already in al-Kindi (ed. Abu Rida, p. 179). An unknown Alexandrian commentator--so we have to assume-realizing that one combination, namely 'irrational and immortal living being' was still missing in the division, discovered this fourth kind of 'living being', which had been neglected by his predecessors, in the demons who are immortal but not endowed with reason. This hypothetical commentator seems to be the source of Abu Bish Matta, a passage of whose commentary on the Isagoge (preserved in the citation of Ibn Matran, Bustan al-atibba', MS U.S. Armed Forces Medical Library, near the end of the book) reads as follows: 'Irrational and immortal-- this refers to the jinns about whom Plato said that they are organs of evil and punishment for the wicked' (---------------------), We may quote a parallel passage from the philosophical introductory part to the medical encyclopedia (al-Mu'alajat al-Buqraiyya) of Abu'l-Hasan al-Tabari (tenth century). In ch. 20, on good and evil, he quotes some ancient philosophers who acknowledged the existence of these principles: Proclus, Plato, Aristotle, Socrates, and Gale (whose passage has been published in the Classical Quarterly, NS VI, 1-2, 1956, 91-2,97). Plato supposedly said that 'rational mortal living being' denotes man, 'rational immortal living being' denotes the angel, 'irrational {im) mortal living being' the evil living beings through whom the wicked are punished; another passage by him is quoted in which he says about the 'satans' that they are the breed of evil, while the angels belong to the good living beings (-------------). (The idea of demons of punishment is not Platonic, but it occurs in later Greek philosophy. Plutarch (Quaest, rom., 51) ascribes to Chrysippus the belief in evil demons appointed by the gods to punish evil-doers and the theme was elaborated by the Neoplatonists; cf. Pauly-Wissowa, Real-enzyklopadie des klassischen Altertums, Suppl., III, 298 (Chrysippus). 304 (Plutarch), 313-14 (Plotinus), 314, 315-19 (Porphyry), 321 (Proclus). These passages were worth quoting at length not only for the interest which they have for their own sake, but because they are also necessary for the explanation of a text which forms a close parallel to the passage in the commentary of the qasida. When the philosopher Miskawayh was asked (in the middle of the tenth century) by his friend Abu Hayyan al-Tawhidi about the proof for the existence of the angels, he gave the following answer (al-Hawamil wa'l-shawamil, 363-4): firstly, the Qur'an and the Sunna are full of references to angels. Secondly, their existence is also proved by reason. "When the intellect makes a division, the things contained in it must be existent if this involves no absurd statement....As the intellect divides the substance to living and not-living beings; the living being to rational and irrational' the rational being to mortal and immortal--there result from this division four things: rational mortal living being, irrational immortal living being, rational immortal being, and irrational mortal living being. The third item in this division consists of the angels.' Miskawayh then explains that there are differences among the angels as to their rank; and finally says that there is another proof for the existence of the angels from their actions, which are manifest in the world, but that his proof would require lengthy prolegomens, for which he has no space in that book. It is obvious that the proof from the vision is identical with that quoted by the commentator of the qasis, who may have taken it either from Miskawayh himself, or from a common source.

Many passages would need similar commentaries; these two examples must, however, suffice here. (For a study of the antecedents of the idea [pp. 5, 51] that of spiritual beings one can only ask two of the four 'types of inquiry'-- whether a thing exists, its quidity, its quality, and its purpose--See A. Altmann and S.M. Stern, Issaac Israeli, Oxford, 1958, 13-23). When put into their proper context, many passages will, in their several ways, add to our knowledge; and students of both Ismailism and Islamic philosophy are greatly indebted to the editors for making this interesting text available. As regards the text, it is based on a unique MS in Istanbul, and the editors have done a great deal to correct it. There is, however, perhaps occasionally still scope for further improvements; e.g. on p. 2, 1. 8, ---- seems wrong (the translation on p. 21 is hardly acceptable)--read perhaps -----; on p. 3, 1.3, a whole sentence seem to have fallen out--read ------; on p. 5, 1.8, read -- for --; in 1. II is wrongly supplied by the editors; in 1. 12 read -- for --; on p. 58, ===, puts the comma after---, and remove it after --- (this changes the meaning completely; the words are left out in the translation, p. 38).